Modafinil vs RAD-140
FDA Approved vs Emerging
avoid Mechanism-based · 53% Both Modafinil and RAD-140 carry hepatotoxic risk. Combining hepatotoxic compounds significantly increases liver damage potential. If unavoidable, include liver support (TUDCA/NAC) and monitor ALT/AST frequently.
Molecular Data
Modafinil RAD-140
Weight 273.35 Da 393.83 Da
Half-life ~12-15 hours ~60 hours
Type Diphenylmethylsulfinylacetamide (C15H15NO2S) Nonsteroidal selective androgen receptor modulator (C20H16ClN5O2)
Key Benefits
Modafinil
01 Sustained wakefulness and alertness for 10-15 hours without the jitteriness of traditional stimulants
02 Enhanced executive function, working memory, and decision-making under fatigue
03 Improved focus and concentration during prolonged cognitive tasks
04 Reduced impulsivity and improved task completion in sleep-deprived individuals
05 Low abuse potential relative to amphetamine-class stimulants (Schedule IV)
06 Minimal impact on normal sleep architecture when taken in the morning
RAD-140
01 Potent anabolic activity in muscle tissue with high oral bioavailability
02 Tissue-selective action sparing the prostate and other androgen-sensitive organs
03 No aromatization to estrogen (no estrogen-related side effects such as water retention or gynecomastia)
04 No conversion to DHT (reduced risk of hair loss and prostate stimulation compared to testosterone)
05 Long half-life (~60 hours) permitting convenient once-daily oral dosing
06 Neuroprotective properties observed in preclinical models
07 Increased lean body mass and reduced fat mass in preclinical studies
Side Effects
Modafinil
Headache (most frequently reported side effect, often dose-dependent)
Insomnia (particularly if taken too late in the day)
Anxiety and nervousness
Appetite suppression and mild nausea
Dry mouth
Dizziness
Gastrointestinal discomfort (diarrhea, abdominal pain)
RAD-140
Testosterone suppression (dose-dependent, occurs in virtually all users by week 4-6)
Liver enzyme elevation (ALT, AST increases reported in clinical and anecdotal data)
Hair shedding (temporary, typically resolves after discontinuation)
Headaches (most common in the first 1-2 weeks, often transient)
Nausea (mild, usually with initial doses or on an empty stomach)
Lipid disruption (HDL suppression, LDL elevation)
Mild insomnia or sleep disturbance
Reduced libido and mood changes related to testosterone suppression
Contraindications
Known hypersensitivity to modafinil or armodafinil
History of Stevens-Johnson Syndrome, TEN, or DRESS with prior modafinil/armodafinil use
Severe hepatic impairment (dose reduction required in moderate impairment)
Unstable angina or recent myocardial infarction
Left ventricular hypertrophy or clinically significant mitral valve prolapse with prior stimulant use
Pregnancy (limited human data; animal studies show teratogenicity at high doses)
Pre-existing liver disease or elevated liver enzymes at baseline
Hormone-sensitive cancers (prostate cancer, certain breast cancers not being treated under clinical supervision)
Pregnancy or potential pregnancy (teratogenic risk from androgen receptor agonism)
Breastfeeding
Age under 25 (incomplete endocrine system maturation and higher risk of HPG axis disruption)
Concurrent use of hepatotoxic medications without medical supervision
Known cardiovascular disease (insufficient safety data for this population)
Research Evidence
Modafinil RAD-140
Status FDA Approved Emerging
References 5 studies 5 studies
Latest — July 2020
FDA Approved Yes No
This comparison is for educational and research purposes only. Consult a healthcare professional before use.